1. Field
Apparatuses and methods consistent with the exemplary embodiments relate to a decoding apparatus, an electronic apparatus, and a controlling method thereof, and more particularly, to a decoding apparatus using two-dimensional conversion and discrete wavelet transform (DWT), an electronic apparatus and a controlling method thereof.
2. Description of the Related Art
Currently, various codecs use a similar method of converting image information in a spatial domain into that in a frequency domain through two-dimensional conversion. Such method commonly places a higher priority in a low-frequency area of the data that is sensitive to human eyes in order to reduce the amount of data corresponding to a high-frequency area when compressing information of an image.
Meanwhile, owing to the advancement in imaging and storing technology, the size of source image files greatly increased over the years, but a pixel value of a minimum size of a block used in the conventional encoding method changed little.
The Audio Video Standard (AVS) 2.0 has introduced discrete wavelet transform (DWT) to the existing scheme to expand an output of two-dimensional conversion from N×N to 2N×2N.
Although the quality of output is degraded compared with the N×N block method, the amount of data is reduced to about ¼. If the conventional method is applied to a large-sized image and to areas with fewer variations, the degraded quality may be restored to the extent that it cannot be recognized by human eyes by adding a small amount of data.
To apply DWT to data to which two-dimensional conversion is performed, separate buffers are required for storing an output of two-dimensional conversion and for storing an output of DWT.
The larger buffer requirements may mean wasted resources and increased cost.